221029993 has 2 divisors, whose sum is σ = 221029994. Its totient is φ = 221029992.

The previous prime is 221029979. The next prime is 221030003. The reversal of 221029993 is 399920122.

221029993 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 221027689 + 2304 = 14867^2 + 48^2 .

It is a cyclic number.

It is not a de Polignac number, because 221029993 - 2⁵ = 221029961 is a prime.

It is not a weakly prime, because it can be changed into another prime (221029973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110514996 + 110514997.

It is an arithmetic number, because the mean of its divisors is an integer number (110514997).

Almost surely, 2^221029993 is an apocalyptic number.

It is an amenable number.

221029993 is a deficient number, since it is larger than the sum of its proper divisors (1).

221029993 is an equidigital number, since it uses as much as digits as its factorization.

221029993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17496, while the sum is 37.

The square root of 221029993 is about 14867.0774868499. The cubic root of 221029993 is about 604.6217091915.

The spelling of 221029993 in words is "two hundred twenty-one million, twenty-nine thousand, nine hundred ninety-three".